Fuel-pump for combustion-engines of the injection type.



J. GNTHER. wm, PUMP Pou oMBUsTwN mmm; 01-1 Tm INJECTION TYPE.

APPLIUATION FILED JAN.2l, 1911, y-Q'L-@p Patented Oct. 8, 1912.

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J'. GNTHER.

FUEL PUMP .FOR (MJM'l'US'lION ENGINES 0F THE INJECTION TYPE.

.MPMUAL'IOH ML110 JAN. 2l, 19H. iik. WDW) 1F immun-m 00u 1912.

JACOB GNTHER, OF BERGISCH GLADBACH, NEAR COLOGNE, GERMANY.

FUEL-PUMP FOR COMBUSTION-ENGINES OF THE INJECTION TYPE.

Specication of Letters Patent.

Patented Oct. 8, 31912.

Application filed January 21, 1911. Serial No. 603,845.

fl'o all whom it may concern:

Be it known that I, JACOB GNTHER, engineer, a subject of the German Emperor, residing at- 109 Laurentiusstrasse, Bergisch Gladbach, near Cologne-on-the-Rhine, Germany, have invented certain new and useful Improvements in Fuel-Pumps for Combustion-Engines of the Injection Type, and do hereby declare the following to be a full,`

clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in fuel pumps for combustion engines of the injection type. In combustion engines of this class the fuel instead of being vaporized within a chamber disposed before the cylinder is directly supplied to the atomizing nozzle at the beginninif of the combustion stroke. Therefore the fuel pump must supply a. large amount of fuel at a considerable speed and within a comparatively short time.

During the first part of the stroke of the plunger the speed of the latter is necessarily very low,l when using driving elements of the ordinary construction, such for example as cranks, eccentrics, cams, etc. Therefore means have heretofore been provided in fuel pumps of this class whereby the fuel discharge from the pump is prevented ,at the beginning of the stroke of the plunger, and when the latter has attained a greater speed, the fuel supply to the nozzle takes place. The driving mechanism is so constructed, that the plunger has the desired speed at the moment when the injection must 'take place. For effecting such a regulation of the fuel supply a back flow valve has been provided which is held in the open position at the beginning of the stroke of the plunger, and 1s closed 'when the plunger has attained the necessary speed, whereupon injection is effected. Afterward the saitvalve is reopened by means controlled by the governor of the engine according to `the load of the engine.

My invention relates more particularly to the regulating means for the fuel supply. And ythe object ofthe improvements is to provide mechanism whereby the complicated reguiation of the back flow valve, that is to say" `the opening of the valve, the closing of tile/same. and finally the reopening of the same in dependence of the governor, is effected in a simple way. For this purpose the said regulating movements are derived from the plunger or its driving mechanism. In both cases the valve is opened by means of an element which is movable with the plunger' of the engine, the first opening of the valve which begins during the suction stroke of the plunger being derived from a part of the plunger or its driving mechanism which has a movement opposite to that of the part from which the second opening movement is derived, which begins during the pressure stroke. As the opening movements of the valve have the same direction in both cases, the movements of the said parts connected with the plunger and movingr in opposite directions must be transmit- `ted to the said valve in opposite senses.

For the purpose of explaining the invention more in detail several examples embodying the same have been shown in the accompanying drawings. ln-said drawings Figure 1 is a vert-ical section of the pump and a side view of the driving and controlling mechanism, and Figs. 2 to 10 are diagrammatical viewsof modifications of the controlling valve and the driving and controlling mechanism.

Referring to the example illustrated in Fig. l, the fuel chamber a of the pump communicates with the cylinder b of the pump through an automatic suction valve c and a bore d, and furthermore through a back flow valve e and the bore d. Fuel is supplied to the fuel chamber a through a pipe g. The pressure valve is indicated by the letter l2., and the fuel discharge tube from the pump to the nozzle of the workingcyliuder by the letter i. A spring l has the tendency to force the plunger c of lthe'pump downward, and the said plunger is forced upward by means of a cam n of the cam shaft or valveoperating shaft and a rocker m engaging said cam. The cam n is constructed with a smoothly ascending portion beginning at the point indicated by the letter t, and with ay rapidly ascending portion beginning at the pointindicated by the letter u. From the point fu which is farthest away from the axis of the shaft the cam gradually approaches the diameter indicated by the letter w along a substantially circular line. il spring o has the tendency to normally seat the back flow valve e, which is adapted to be opened from two 'dilferent parts of the plunger or its driving mechanism. The rst opening operation is performed during thel suction stroke by means of a stud p secured to the plunger ,7cand a rocking lever g pivotally mounted on a suitable part of the frame of 4the pump and adapted to be engaged at one end by the stud p and to engage with the opposite end the stem of the valve e. Thesecond opening operation of the back flow valve which takes place durin the pressure stroke of the plunger is ected by means of the surface s of a block r which is pivotally mounted on the rocker m. The surface s is disposed eccentrically of the fulcrum of the block 1" on the rocker m, and the block 7' is operatively connected with the governor of the. engine by means of a lever m and other elements not shown in the figure. The connection between the governor and the abutment is such, that in case of an increase in the load and a decrease inthe speed ofthe engine below the normal the lever is rocked 4upward and the block 7' to the left, Yso that the surface s engages the stem of the valve e at a later moment, and the fuel supply from the pump' is increased. p

The operation of the pump is as follows: Wien the part v of the cam n which is farthest away from the aXis'of the cam shaft has passed beyond the rocker m, and rotation of the said shaft continues, the rocker m is gradually lowered by riding on the descending portion of the cam, and consequently the spring Z'is at liberty to force the plunger c downward so that the latter performs its suction stroke.; ,By such downward movement fuel is drawn into the cylinder b through the suction valve c. Before the end of the suctio'n stroke is attained, the stud p strikes against the rocking lever g and thereby throws the opposite end of the latter upward, so as to open the back flow valve e against the action of the spring 0. ln the meantime the abutment r is moving downward and away from the stem of the valve e. While the rocker m is riding on the surface fw the plunger' Ic is at rest, and the valve e remains open, so that the cylinder b is completely filled when the pressure stroke begins. l hen the point t of the cam arrives below the rocker m the plunger lc begins to slowly move upward while the valve e is still unseated, because the stud p remains in contact with the lever g. lherefore at the beginning of the pressure stroke, and while the cam a is moving fromA the point ii to the point u, no-fuel supplied by the pump. "When the point es arrives below the rocker m and the portion of the cam indicated by "the letters 'u--fv comes into cperation, the stud ya has risen suliciently to release the rechi-ng lever Therefore the valve e is closed by its spring o, and the fuel is discharged through the tube z' and to the fuel noz'zle of thev working cylinder. The speed with which the fuel is thus discharged is comparatively great, because the plunger has assumed a high speed by the action of the rapidly rising portion u t'o v of the cam n. When a part of the cam surface which is near' the point o comes into engagement with the rocker ai, the surface s of the abutment r has been raised so far,

that it strikes against the stem of the'valve e so as to open the latter and stop the fuel supply to the nozzle. The moment at which the valve is thus unseated is controlled by the governor.

The position of the stud p relatively to the rocking lever g is such, that it is just disengaged from the latter when the rocker m rides on the part u of thecam n.

The mechanism for operating the back flow valve may be constructed in different ways, and several forms of this mechanism are illust-rated in Figs. 2 to 10. For the sake of simplicity, the automatic suction valve and the automatic pressure valve have been omitted from these figures, it being understood however that these valves are to be used, so that three valves will be present in each ofthe structures. One modiication of such mechanism is shown in Fig. 2 of the drawings. In the example shown a rocker m2 is pivotally mounted at one end on a relatively fixedpart of the frame of the pump. At its left hand end. the rocker m2 is adapted to be engaged by a stud p2 secured to the plunger le?, and at a point.

intermediate between the stud p2 and its fulcrum the rocker is adapted to be engaged by a cam An2 revolvingwith the val ve-operating shaft. Furthermore the rocker carries a block r2 which is adapted to be set by the governor according to the load of the engine. The rocker 'm2 is further provided with an arm in which at its upper end is formed with a hook whereby it engages the free end of a rocking lever Q2.

The elements indicated in Fig. 2 by the letters k2, mi', etc. correspond to the elements which in Fig. l have received similar letters of reference. parts is similar to that described with reference to Fig. l. While the plunger 7a2 performs its downward stroke the valve c2 is iopened by the lever g2 operated by the hook at the upper end of the arm p, moved downward with the plunger k2 under the influence of the stud p2. During the first part of the pressure stroke 'the valve ci is held apen by the stud p2 which is moving upward The operation of the various.

fuel Idischarge to the fuel nozzle of the working cylinder begins at high speed. Near the end of the pressure stroke of the plunger the cam n2 has raised the block 'f2 sn'tli ciently to again unseat t-he valve e2, so that the fuel supply is again stopped. The block 'lf2 is set by the governor in thesame way as has been described with reference to the block 1' shown in Fig. 1.

In Fig. 3, I have shown a modification of the example illustrated in Fig. 2, the arm p3 which corresponds to t-he arm p being disposed at the opposite side of the stem of the valve c3. Accordingly the fulcrum of the rocking lever ([3 is likewise on the oppo site side of the said stem. The operation of the mechanism is the same as that ot the mechanism shown in Fig. 2, as will readily he understood from the ligure.

In Fig. 4, I have sho-wn a further modification of the invention. The constructioni of the mechanism corresponds to that shown in Figs. 2 and 3, with the exception, 'that the arm p* which corresponds to the arm 71 or p3 is disposed at the opposite side of the fulcrum of the lever mi* for which purpose the latter is provided with a rearward extension. The said arm engages the lever o from below. The fulcrum of the lever /74 may also be disposed at the right hand side ot' the stem of the valve e4. as is indicated in Fig. 5. The operation of the mechanismshown in Figs. 4 and 5 is the same as that of the devices shown in Figs. 2 and 3, and it will be understood without further description.

In the modification shown in Fig. 6 the fulcrum of the rocker m is disposed on the side of the plunger le which is opposite to that of the stem ot' the valve c and its operating parts, and the block r is mounted on the free end of the said rocker. The stud p is secured to the rod e of the pilinger icc. rl`he operation of the mechanism will readily be understood without further explanation.

The example shown in Fig. 7 similar to that shown in Fig. 6. But instead of the stud 7) an arm ,v7 is provided on a rearward extension of the rocker mi and the rocking lever 77 is accordingly mounted on the right hand side ofthe/stem of the valve e7. In the example shown in Figs. t and 7 the direction of the movement of the plunger-s u and N respectively is transmitted in the reversed direction to the stem ot' the valves c and e7 respectively by means of the levers y and Q7.

Fig. 8 shows a similar example in which the lever (78 and the arm p8 are disposed in a different way, the arm p8 being disposed on an extension of the rocker rm,8 toward the left. In View of the fact, that in this construction the movement of the plunger is transmitted to the valve es with a considerable reduction, the arrangement is particularly adapted for pumps in which the stroke of the valve e8 is but small.

The example shown in Fig. 9 is'dill'ercnt from those descrihedabove in this respect, that lthe back How valve e opens outward .instead of inward. Therefore the head of the valve stem is not raised by the block 1' 'but pulled downward. For this purpose the valve stem is slotted at its lower end and the block r is constructed in the form of an arm which projects through the slot of the stem. In a similar way the movement of the valve stem by the arm qs is modified. The upward movement of the plunger during its pressure stroke is reversed by mounting the arm rf on the side of the fulcrum of the rocker m which is opposite to the plunger' 1. The arm p may be arranged in various ways. as will readily suggesbitselt to, those skilled in the art from the examples described in Figs. 1 to 8. In the example shown in Fig. 9 the said arrangement is similar to that shown 1n Fig. 2.

In the example shown in Fig. 10 the block 110 for openin'o' the valve eL0 during `the pressure stroke ,of the plunger of the pump is mounted on the valve stem. Otherwise the operating mechanism may be constructed in any preferred way.

Instead of providing a special hack flow valve, the suction valve of the pump may be operated in such a way as to perform the function of the back [low valve. In this case the suction valve is moved in part automatieally by its spring and in part positively by mechanism similar to that used in combination with the valve c as described with reference to Fig. 1.

I claim herein as my invention:

l. In a lucl pump for internal combustion engines, the combination of the cylinder, its plunger, a fuel-supply, a valve controlling the connection of said 'fuel-supply with the pump cylinder, mechanical means operating in unison with the plunger for holding said valve open during the first part of the plungers pressure stroke, mechanical means, also operating in unison with the plunger, for :opening said valve near the end of said pressure stroke, and means for closing said ,valve during the intervening portion ofthe pressure stroke.

2. In a fuel pump for internal combustion engines, the combination of the cylinder, its plunger, a fuel-supply, a valve controlling the connection of said fuel-supply with the pump cylinder, a spring having a tendency to close said valve, Vmechanical means operating in unison with the plunger and in opposition to said spring, for holding the valve open duringr the first part ot' the plungers pressure stroke, and mechanical means, also operating in unison with the plunger and in opposition to the spring, for opening said. valve near the end ol the pressure stroke, said' spring operating to close the valve dur- (ing the intervening portion of the pressure stroke.

ln a fuel pump for internal combustion engines, the combination of the cylinder, its plunger, a fuel-supply, a valve-controlling the connection or saidl lueksupply with the pump cylinder, mechanical means for holding said valve open during. the rst parto the plunger's pressure stroke, mechanical means :tor opening the valve near the end ot the pressure stroke, governor-controlled means tor varying` the timing of the lastnamed mechanism, and means for closing said valve during the intervening portion of the pressure stroke. y

e., ln a fuel pump for internal combustion engines, the combination. of the pump cylinder, its plunger, a fuel-supply, means for mintrolling, the connection between the fuelsupply and the pump cylinder, mecl'ianism operatiim;y on said means during the plungers suction stroke and to keep it open during the i'irst part of the pressure stroke, mechanism operating` on said means near the enel et the plungerls pressure stroke to again open communication between the cylinder and the fuel-supply, and a devicefor keeping said controlling means, during the inter-- veiling portion oit the pressure stroke, in a position in which said means interrupts the connection between the `fuel-supply and the pump cylinder.

. 5. ln a fuel pump for internal combustion engines, the combination of the pump cylinder, its jlunger, a tuel-supply, a valve controlling the connection between the fuelsupply and' the pump cylinder, a lever operating to open said valve during` the suction stroke to keep it open during the first part et the pressure stroke, another ever operating to open said valve near the end ot the plungers pressure stroke, and means tor closing said valve during the interveningA portion of the pressure stroke.

(bln a `tuel pump for internal combustion engines, a pump cylinder, its plunger, a fuelsupply, a valve controlling the connection ot the pump cylinder with the fuel-supply, two studs connected with the plunger, mechanism adapted to be engaged by one et said studs to hold said valve open from a noaaeee `time shortly beforel the end of the suction stroke to a time shortly after the beginning ot the pressure stroke, nieclianism, adapted to be engaged by the other stud, for opening the said valve at a later period of the pressure stroke, and means for closing said valve during the intervening portion of the pressure stroke.

7. ln a fuel pump :tor internal combustion engines, a pump cylinder, its plunger, a fuelsupply, a valve controlling the connection of the pump cylinder with the 'fuel-supply, .two studs connected with the plunger, mechanism adapted to be engaged by one oil said studs and to hold said valve open from a time shortly before' the end of the suction stroke to a time shortly after the beginning of the pressure stroke, mechanism, adapted to be engaged by the other stud, for opening the said valve at a later period of the pressure stroke, said last-named mechanism comprising a valve-operating member movable relatively to the other parts of said mechanism, and governor-controlled means for shitting said member to vary the ltime at which the valve is-opened during the 'pressure stroke, l

and means for closinU said valve 'during the intervening portion or the pressure stroke.

l 8. lin fuel pump for internal combustion engines, a pump cylinder, its plunger, a fuelsupply, a valve opening toward the fuelsupply and controlling its connection with the pump cylinder, two studs connected with 'the plunger, mechanism adapted to be engaged by one of said studs, and to hold said valve open from a time shortly before the end of the suction stroke toa time shortly after the beginning et the pressure stroke, an operating` shaft, a lever arranged to be rocked by said shaft and to engage the other stud to operate the plunger, a valve-operating member secured to said lever at a point between its fulcrum and the operating shaft to open the valve at a later period of the pressure stroke, and means for closing said valve during the intervening,` portion of the pressure stroke.

ln testimony, that l claim the foregoing as my invention, l have signed my name in presence oit two subscribing witnesses.

JAQUE Glll'ilrllllillt. ll/litnesses:

Louis "Vannonr, Bnssre l?. Delmar. 

